a) Field of the Invention
This invention relates to an intra-line fishing rod having improved properties for passing the fishline therethrough. For the intra-line fishing rod, annular fishline guides or a spiral fishline guide are provided within a rod tube which is formed with an improved inner surface which reduces interior frictional resistance on the fishline. This invention also relates to an improved method by which a rod tube comprises a thermosetting resin or a thermoplastic resin as a matrix, and is reinforced by reinforced fibers, whereby the fishline guide member is formed on the inner surface of the rod tube.
b) Description of Related Art
Conventional intra-line fishing rods suffer from numerous drawbacks which reduce rod strength, hinder performance, and tend to damage the fishline.
Japanese Patent Unexamined Publication No. 4-341133 discloses a fishing rod in which annular fishline guides for a fishline, made of a monofilament of fibers, are molded integrally on an inner peripheral surface of a rod tube so as to enhance the sliding movement of the fishline. Japanese Utility Model Unexamined Publication No. 5-88259 discloses a tubular member such as a rod tube in which a prepreg for constituting the rod tube is wound on a resin tape wound spirally on a metal core, so that a spiral protuberance (guide for a fishline) is integrally formed at the same time, using this prepreg.
However, when the guides are to be formed integrally on the inner surface of the rod tube, a prepreg is wound on a metal core, and is heated while being pressurized by a tightening tape. In the construction disclosed in Japanese Patent Unexamined Publication No. 4-341133, because of the presence of the guides, the fibers are arranged in a generally meandering manner in the direction of the axis of the rod tube, or the flow of a resin of the prepreg becomes uneven. In the construction disclosed in the Japanese Utility Model Unexamined Publication No. 5-88259, the presence of the resin tape, likewise causes the fibers to be arranged in a generally meandering manner in the direction of the axis of the rod tube, and causes the flow of a resin of the prepreg to become uneven. As a result, the strength of the rod tube is reduced, and is liable to be broken.
Furthermore, the guides formed integrally on the inner surface of the rod tube exert a great influence on the strength of the rod tube when the rod tube is flexed, and the flexural strength of the rod tube is lowered by the concentration of stresses depending on the configuration, construction and material of the guides, which leads to a possibility that the rod tube is broken during the fishing operation. Namely, it is thought that in the conventional rod tubes, sufficient consideration has not been given to the details of the guides and those portions of the rod tubes in the vicinity of the guides.
Japanese Patent Unexamined Publication No. 1-304836 discloses an intra-line fishing rod having a spiral fishline guide provided therein. This construction, in which the continuous spiral fishline guide is provided within a rod tube, is simpler as compared with a construction in which a plurality of annular fishline guides are provided within a rod tube.
However, the spiral guide has an end portion, and when the fishline is to be passed through the rod tube, the fishline is caught by this end portion and often damaged, and even if the fishline is not damaged or cut, the resistance to the passage of the fishline is increased. In such a case, the fishline guide causes reduced efficiency and performance of the intra-line fishing rod.
In an intra-line fishing rod, a fishline is passed through a narrow bore or space in a rod tube, and generally the fishline moves in contact with an inner surface of the rod tube. Therefore, if the inner surface is coarse or rough, a frictional resistance to the fishline is increased, so that the fishline is damaged by increased frictional heat, and also the inner surface of the rod tube is susceptible to damage. If the inner surface is thus damaged, the fishline is damaged by it.
Japanese Patent Unexamined Publication No. 5-268858 discloses an intra-line fishing rod in which a resin layer containing fluoroplastic particles or a resin layer of ultra-high-molecular-weight polyethylene is formed on an inner surface of a rod tube so as to prevent a fishline from adhering to the inner surface of the rod tube and also to smoothly guide the fishline.
In the fishing rod disclosed in Japanese Patent Unexamined Publication No. 5-268858, a material, having a good water repellency and a low friction coefficient, is used, and therefore water drops hardly deposit on the inner surface of the rod tube, and the resistance to the fishline is not increased by water drops. However, even with the use of fluoroplastic particles having a low friction coefficient, if the inner surface of the rod tube is coarse, this inner surface still remains coarse even when a mixture of such fluoroplastic particles and a resin coating is coated onto the inner surface of the rod tube, and as a result the resistance to the passage of the fishline is increased as described above.
In the case where a film of ultra-high-molecular-weight polyethylene is wound on a metal core, and then is baked together with a prepreg, the inner surface of the resultant rod tube is coarse depending on a coarse surface of the metal core. As a result, the frictional resistance on the fishline passing through the rod is increased.
With regard to prior art methods for forming intra-line fishing rods, Japanese Patent Unexamined Publication No. 4-341133 discloses a method in which annular fishline guides each made of a monofilament of fibers, are formed integrally on an inner surface of a rod tube so as to enhance the sliding movement of the fishline and also to prevent the inner surface of the rod tube from being damaged by wear. More specifically, the monofilaments of fibers are wound on suitable portions of an outer peripheral surface of a mandrel, and then a prepreg is wound thereon to form the rod tube of an integral construction according to an ordinary method. There is also disclosed a method in which step portions are formed in a mandrel, and annular fishline guides are positioned at these step portions, respectively, and then a prepreg is wound thereon.
With this conventional method, however, the inner surfaces of the annular fishline guides are held in intimate contact with the surface of the mandrel, and therefore when the prepreg is wound thereon, the prepreg is radially outwardly convex in the vicinity of the annular fishline guides, and the other portions of the prepreg is held in contact with the mandrel along the surface of the mandrel. Namely, in the molding of the rod tube using the prepreg, the inner surface of the rod tube coincides with the inner surfaces of the annular fishline guides in the axial direction, and the annular fishline guides will not project from the inner surface of the rod tube. During the hot molding, resin flows from the prepreg into the surface of the mandrel, so that the annular fishline guides are embedded in the resin. As a result, the annular fishline guides are not exposed to the inner surface of the rod tube.
Even if the inner surface of the annular fishline guide is partly exposed, burrs of the resin are usually formed around the thus exposed portion. In this condition, if the fishline is guided through the rod, the fishline may be damaged by the burrs of the resin, thus the stable fishline guide function can not be performed.
Even in the case where the positioning step portions are provided on the mandrel, the annular fishline guides are similarly embedded in the resin since the monofilament of fibers has a relatively small diameter.
In addition to these problems, there is another problem that the prepreg is outwardly convex in the vicinity of the annular fishline guides as described above, so that the fibers meander, which reduces the strength of the rod tube.
The need therefore exists for an intra-line fishing rod and method for manufacturing the same which overcomes the drawbacks outlined above with regard to the prior art.
It is therefore an object of this invention to provide an intra-line fishing rod of a high strength in which a guide is projectingly formed integrally on an inner surface of a rod tube, and those portions of the rod tube in the vicinity of the guide are prevented from being reduced in strength.
To achieve this objective, the present invention provides an intra-line fishing rod wherein a rod tube comprises a synthetic resin as a matrix, and is reinforced by reinforced fibers; and a guide is formed integrally with and projects from an inner surface of the rod tube; characterized in that a cushioning portion is formed between the guide and a body layer of the rod tube which is composed predominantly of axially-extending fibers; and cushioning portions are formed respectively at front and rear sides of the guide connected to the inner surface of the rod tube; and the cushioning portions are smaller in bending modulus than a bulge portion region of the guide for contact with a fishline.
It is noted that the term xe2x80x9cbending modulusxe2x80x9d means a resistance force (rigidity) to the bending of the rod tube in a flexing direction per unit transverse area of the rod tube.
In the invention described above, the cushioning portions with a small bending modulus are formed respectively between the guide and the body layer and at the front and rear sides of the guide. Therefore, when the rod tube is flexed, the resistance due to the flexural rigidity of the guide is reduced, and the concentration of stresses on the rod tube is prevented, and the strength of the rod tube is increased.
The present invention also provides an intra-line fishing rod wherein a rod tube comprises a synthetic resin as a matrix, and is reinforced by reinforced fibers; and a guide is formed integrally with and projects from an inner surface of the rod tube; characterized in that the guide comprises a synthetic resin as a matrix; a bulge portion region of the guide for contact with a fishline has a higher content of a reinforcement; and either synthetic resin regions or synthetic resin-reinforcement mixture regions having a higher synthetic resin content are provided respectively at front and rear sides of the bulge portion region and between the bulge portion region and a body layer of the rod tube having the fibers oriented generally in the direction of an axis of the rod tube.
In the present invention, with respect to the guide formed of FRP or the like, the bulge portion region contains a higher reinforcement content, and that portion between the bulge portion region and the body layer of the rod tube, as well as those portions disposed respectively at the front and rear sides of the bulge portion region, has a higher synthetic resin content. With this construction, the guide is connected to the rod tube at its low-rigidity portions lower in flexural rigidity than the bulge portion region. Therefore, when the rod tube is flexed, the resistance due to the flexural rigidity of the bulge portion region is reduced, and the concentration of stresses on the rod tube is prevented, and the strength of the rod tube is increased.
The invention further provides an intra-line fishing rod wherein a rod tube comprises a synthetic resin as a matrix, and is reinforced by reinforced fibers; and a guide is formed integrally with and projects from an inner surface of the rod tube; characterized in that the guide has an outer side surface extending generally along the inner surface of the rod tube disposed at the front and rear sides of the guide, and in that a number of the guides may be formed of a synthetic resin, and may be spaced at short intervals along a length of the rod tube.
With this arrangement, if the guide is formed of a synthetic resin, the area of contact of the guide with the fishline is not constant, although if only one guide is provided, the guide can be easily damaged by the frictional resistance developing between the guide and a fishline, and hence is susceptible to wear. However, if a number of guides are provided at short intervals at a small-diameter portion of the rod tube (as at the end portion adjacent to the tip top of the rod tube), the above wear can be prevented. And besides, since the guides are formed of the synthetic resin, they will not offer a large resistance to the flexing of the rod tube, and the concentration of stresses is prevented, and the strength of the rod tube is increased.
The present invention further provides an intra-line fishing rod wherein a rod tube comprises a synthetic resin as a matrix, and is reinforced by reinforced fibers; and a guide is formed integrally with and projects from an inner surface of the rod tube; characterized in that a curved surface of a bottom portion of the guide connected to the inner surface of the rod tube is defined by a concavely-curved surface which is gentler than a convexly-curved surface covering the top and a side surface of the guide.
With this arrangement, the guide is formed into a suitable configuration, and the bottom portion of the guide connected to the inner surface of the rod tube is defined by the concavely-curved surface which is gentler than the convexly-curved surface in the vicinity of bulge portion region. Therefore, the bottom portion of the guide portion is progressively decreasing in thickness, so that the concentration of stresses is reduced when the rod tube is flexed, and the strength of the rod tube is increased.
The invention also discloses an intra-line fishing rod wherein a rod tube comprises a synthetic resin as a matrix, and is reinforced by reinforced fibers; and a guide is formed integrally with and projects from an inner surface of the rod tube; characterized in that the guide spirally extends continuously; and a distal end portion of the guide is densely arranged in contact with the inner surface of an end portion of the rod tube over a predetermined length along an axis of the rod tube.
With this construction, the distal end portion of the spiral guide is densely arranged in contact with the inner surface of the end portion of the rod tube over a predetermined length along the axis of the rod tube. With this construction, even if stresses concentrate on the end portion of the rod tube in the vicinity of the guide, the end portion of the rod tube is prevented from damage since its strength is increased. For connection purposes, the end portion of the rod tube is originally designed to have a greater strength than the other portions, and this can be achieved by densely arranging the guide, and besides the fishline is prevented from being caught by the end of the guide.
It is also an object of this invention to provide an intra-line fishing rod in which a fishline can be smoothly passed through a rod tube, and the fishline and the inner surface of the rod tube are hardly damaged.
To achieve the above object, the present invention provides an intra-line fishing rod characterized in that an inner surface of that region of a rod tube where a fishline guide is not provided, and a fishline is to be passed, or that surface of a fishline guide for contact with the fishline which fishline guide is formed on and projects from the inner surface of the rod tube, is formed into a mirror surface-like smooth surface.
The surface through which the fishline is to be passed, or the surface for contact with the fishline is formed into the mirror-like smooth surface. With this construction, the resistance to the passage of the fishline is reduced, and the friction is reduced, so that the fishline and the inner surface of the rod tube are less liable to damage. The term xe2x80x9cmirror-like smooth surfacexe2x80x9d means a surface having surface roughness of not more than about 2xcexc, and preferably not more than about 1xcexc. Here, so-called undulations, waving at a larger pitch as compared with the surface roughness, are not taken into consideration.
It is further an object of this invention to provide a construction in which an end portion of a continuous guide is so treated as to prevent a fishline from damage and also to reduce passage resistance.
To achieve the above object, the present invention provides an intra-line fishing rod characterized in that an annular guide member is provided at an end of a continuous guide mounted within a rod tube. Examples of the continuous guide include a single spiral guide, a combination of spiral guides, and a guide structure having a plurality of annular guides interconnected by a wire member or the like in a longitudinal direction. The annular guide member can be formed by tightly winding the end portion of the continuous guide. The annular guide member can also be formed by a separate guide member connected to the continuous guide.
In this construction, the annular guide member is provided at the end of the continuous guide, and a fishline is guided by the annular guide member at the end of the continuous guide. Therefore, the fishline will not be caught by this end, and the resistance to the passage of the fishline is prevented from increasing.
The invention also provides an intra-line fishing rod in which the inner diameter of the annular guide member is smaller than the inner diameter of that portion of the continuous guide disposed adjacent to the annular guide member.
In this construction, the inner diameter of the annular guide member is smaller than the inner diameter of that portion of the continuous guide disposed adjacent to the annular guide member. Therefore, even when the fishline is shaken, the shaking is reduced by this annular guide member. As a result, the contact of the fishline with the inner surface of the rod tube is reduced, and the fishline is prevented from contacting water drops on this inner surface, and therefore the resistance to the passage of the fishline is reduced.
It is further an object of this invention to provide a method of producing a fishing rod, in which a fishline guide is stably exposed to an inner surface of a rod tube, while preventing the meandering of fibers, and a fishline can be smoothly guided, thus reducing the resistance to the passage of the fishline.
According to a first aspect of the invention to achieve this objective in which a fishline guide is stably exposed to an inner surface of a rod tube, while preventing the meandering of fibers, there is provided a method of producing an intra-line fishing rod having a rod tube which comprises a resin as a matrix, and is reinforced by reinforced fibers, a fishline being passed through the rod tube; the method being characterized by the steps of:
winding a thick winding member on a surface of a mandrel in such a manner that a gap for receiving a fishline guide member is formed between opposite side edges thereof;
covering the gap with a thin soft member;
providing the fishline guide member in and along the gap through the thin soft member;
winding a fiber-reinforced prepreg, impregnated with or containing the resin, on the mandrel over the fishline guide member, and applying heat and pressure to the prepreg to form the rod tube; and
subsequently withdrawing the mandrel, and removing the thick winding member and the thin soft member.
In this first method of the invention, the thick winding member is wound on the mandrel in a manner to provide the gap for receiving the fishline guide member. The fishline guide member is thus provided in and along this gap, and the prepreg is wound over the fishline guide member, and is molded to form the rod tube having the fishline guide member projecting from the inner surface of the rod tube. In this method, the resin flows from the prepreg into clearances (in the above gap) between the fishline guide member and the side edges of the thick winding member, and when this resin is set, the fishline guide member is fixedly secured to the rod tube. However, the resin forms corners or angles on the surface of the fishline guide member, which leads to a possibility that the fishline is damaged or cut upon contact with such corners. Therefore, in this invention, the above gap is covered with the thin soft member, and the fishline guide is provided along the gap through this thin soft member. With this arrangement, the fishline guide member, covered by the resin flowed into the region around the fishline guide member, has such a cross-sectional shape that that surface of the fishline guide member projecting radially inwardly from the inner surface of the rod tube is smooth. As a result, the fishline guide member can guide the fishline smoothly. The winding member and the soft member can be easily removed after the mandrel is withdrawn.
According to a second aspect of the invention to achieve this objective in which a fishline guide is stably exposed to an inner surface of a rod tube, while preventing the meandering of fibers, there is provided a method of producing an intra-line fishing rod having a rod tube which comprises a resin as a matrix, and is reinforced by reinforced fibers, a fishline being passed through the rod tube; the method being characterized by the steps of:
winding a thick winding member on a surface of a mandrel in such a manner that opposite side edge portions thereof overlap each other;
covering a step portion, formed between the boundary between the overlapping portions and open portions of the winding member, with a thin soft member;
providing a fishline guide member in and along the step portion through the thin soft member;
winding a fiber-reinforced prepreg, impregnated with or containing the resin, on the mandrel over the fishline guide member, and applying heat and pressure to the prepreg to form the rod tube; and
subsequently withdrawing the mandrel, and removing the thick winding member and the thin soft member.
In this second method of the invention, instead of the gap in the first method, there is utilized the step portion formed at the boundary between the overlapping portions and the open portions of the winding member, and this step portion is covered with the thin soft member, and the fishline guide member is provided in and along this step portion through the thin soft member, and the prepreg is wound thereon. By doing so, any corner is prevented from being formed. The other procedure is the same as that of the first method.
According to a third aspect of the invention to achieve this objective in which a fishline guide is stably exposed to an inner surface of a rod tube, while preventing the meandering of fibers, there is provided a method of producing an intra-line fishing rod having a rod tube which comprises a resin as a matrix, and is reinforced by reinforced fibers, a fishline being passed through the rod tube; the method being characterized by the steps of:
winding a winding member on a surface of a mandrel, the winding member having a groove formed in its surface for receiving a fishline guide member;
providing the fishline guide member in and along the groove;
winding a fiber-reinforced prepreg, impregnated with or containing the resin, on the mandrel over the fishline guide member, and applying heat and pressure to the prepreg to form the rod tube; and
subsequently withdrawing the mandrel, and removing the winding member.
In this third method of the invention, the groove is formed in the winding member, and this winding member is wound on the mandrel, and then the fishing guide member is provided in and along this groove, and the prepreg is wound thereon, and the molding is effected. As a result, the fishline guide member is fixedly secured to the rod tube by the fluidized resin of the prepreg, and the fishline guide member stably projects from the inner surface of the rod tube.
If the groove has such a cross-section that the resin flowed into the groove forms corners, the groove is covered with a thin soft member much smaller than the depth of the groove as in the first and second method, and then the fishline guide is provided along the groove through this thin soft member. By doing so, any corner is not formed.
These and other advantages of the present invention will become apparent with reference to the following drawings and the detailed description thereof provided below.